This invention relates to a magnetic disk device (unit), and more particularly to a magnetic head support mechanism, having an excellent impact-resistant performance, and a magnetic disk device using this support mechanism.
It is reported (in IEEE Trans. Vol.31 No.6 p.3006 to 3008) that in conventional magnetic disk devices, when a large impact is applied in a direction perpendicular to a disk surface, a slider jumps off the disk surface, and is tilted in this jumped condition, and then is brought into contact with the disk surface at a corner portion of its flying rail, thereby damaging the disk surface. It is also reported in this literature that it is effective to provide xe2x80x9ca jump stopxe2x80x9d above the slider in order to reduce the damage of the disk by the above impact.
JP-A-8-102159 discloses a mechanism in which pin projections (limiter portions) are formed on a cover and a base of a magnetic disk device, and even if the magnetic disk device receives an impact, so that a suspension, having a magnetic head mounted on its free end, is shaken, the suspension is brought into contact with the pin projection at its free end, and therefore is prevented from being further displaced toward the base or the cover.
In the above conventional mechanisms, the height (amount) of jumping of the slider off the disk surface is limited by the jump stop or the pin projections, and hence is kept to below a predetermined level, thereby reducing the speed and acceleration at which the slider impinges on the disk. By doing so, damage to the slider and the disk upon impingement is reduced so as to enhance the impact performance of the magnetic disk device.
On the other hand, the degree of damage is determined by the magnitude of the speed and acceleration, at which the slider is brought into contact with the disk, and the size of the area of contact therebetween. More specifically, the contact area much varies in dependent on whether the flying surface (which is opposed to the disk surface, and produces a flying force) of the slider comes into contact with the disk surface in parallel relation thereto, or a corner portion of the flying surface or a bleed surface (which is opposed to the disk surface, and does not produce a flying force) comes into contact with the disk surface as a result of rotation (tilting) of the slider. Therefore, even if the slider comes into contact with the disk surface at the same speed or acceleration, the contact surface pressure (stress) much varies in dependent on the area of contact between the two, that is, the posture of the slider impinging on the disk surface. As a result, the degree of damage much varies. In the above prior art techniques, this is not taken into consideration.
In other words, by controlling the posture of the slider, obtained when the slider, once jumped upon application of an impact, again comes into contact with the disk surface, the proper contact area can be secured (that is, the reduction of the contact area can be prevented), and the contact surface pressure (stress) and hence the damage can be reduced.
A magnetic disk device, having a load-unload mechanism, suffers from a problem that at the time of an unloading operation in which a slider, flying over a rotating disk surface, is separated (moved away) from the disk surface, if the unloading operation is forcibly effected, a flexible flexure is damaged since the slider sticks to the disk surface (if the slider is of the negative pressure-assisted type), so that the slider can not fly in a stable manner.
In the light of the above-mentioned problems, it is an object of this invention to provide a magnetic disk device in which even if a slider jumps off a disk surface when the magnetic disk device receives an impact, the amount of movement of the slider away from a pivot is limited, and also the deformation of a gimbal is prevented.
Another object of the invention is to provide a magnetic head support mechanism in which the posture of a slider, obtained when the slider again comes into contact with the disk, is controlled so as to prevent the reduction of a contact area and also to prevent contact damage, thereby enhancing an impact-resistant performance.
A further object of the invention is to provide a magnetic head support mechanism suitable for use in combination with a load-unload mechanism.
A magnetic head support mechanism of the present invention comprises a slider, which has a magnetic head mounted thereon, and can fly over a rotating disk surface, and a suspension which holds the slider, and presses the slider toward the disk surface from a reverse surface (facing away from a flying surface of the slider facing the disk surface) of the slider, and an air inflow-end of the slider and a beam portion of the suspension are connected together by a flexible member. With this construction, the ability of the slider to follow the rotating disk surface will not be lowered, and besides the slider is prevented from being much rotated upon application of an external impact or the like. Here, this flexible member is referred to as xe2x80x9cslider posture control mechanismxe2x80x9d. Thanks to the provision of this slider posture control mechanism, the slider will not be much moved away from the beam portion at the time of an unloading operation, and therefore flexible finger portions will not be deformed.